Esther Ritmeester was a daugher of Joseph Ritmeester and Aaltje Brander. She married in Amsterdam on 7 April 1937 to Hijman Beesmer, son of Abraham Beesemer and Vrouwtje Drukker.
City Archive of Amsterdam, archive card of Joseph Ritmeester and Hijman Beesemer.
In addition, a Jokos file (number 17482) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.